In the production and design of electronic credit cards (Smart Cards) or other powered credentials (such as, for example, passports, gift cards, debit card, identification cards, etc.), emphasis is placed on conserving battery power in order to prolong the life of the electronic credential. Power consumption of the battery has traditionally been conserved by limiting functionality and utilizing just-in-time manufacturing practices to reduce the amount of time an electronic card sits in inventory and depleting battery life.
In current manufacturing processes, when the circuit of the electronic card is assembled, the circuit begins consuming power from an onboard battery immediately. For example, in cards including capacitive buttons, the circuit continuously monitors for a capacitive change in the button (e.g., resulting from button depression). To monitor for a capacitive change, an integrated circuit (IC) generates a voltage signal to determine the capacitance at the button. If there is large enough change in capacitance, the card activates one or more additional functions. The IC continuously polls the button to identify capacitive changes. Polling may occur every 1-2 seconds, depleting power from the battery when the card is in storage and/or transit. In some cases, the capacitive button is activated during storage or transportation causing larger power drain. In current manufacturing processes, as soon as the battery is connected to the circuit, the circuit begins to draw power from the battery.
Activation of powered cards is normally performed by a mechanical switch or a capacitive sense switch. The switch may be pressed to generate a connection allowing power to activate one or more card functions. The switch must be pressed by a user to activate the card. Pushing a button may be difficult for the user, for example, due to resistive force, advanced age of a user, or physical ailment that prevents operation of the button, etc. Capacitive sense buttons do not provide the reliability needed for some activations and use a large amount of power over the life of the card, limiting the cards use for other applications.